Many portable products, such as cell phones, laptop computers, personal data assistants (PDAs) and the like, utilize a processing system that executes programs, such as communication and multimedia programs. A processing system for such products may include multiple processors, complex memory systems including multi-levels of caches for storing instructions and data, controllers, peripheral devices such as communication interfaces, and fixed function logic blocks configured, for example, on a single chip.
In multiprocessor portable systems, including smartphones, tablets, and the like, an applications processor may be used to coordinate operations among a number of embedded processors. The host application processor may also provide an access port to storage elements such as embedded or removable non-volatile memory modules and disk drives. Other embedded processors may be dedicated to specific real-time operations, such as a modem control processor, an audio signal processor, or the like. Each of the embedded processors may operate their own file system which may have specific time constraints associated with its dedicated functions. Such a multiprocessor system may also be required to share memory storage, such as the embedded memory and removable non-volatile memory modules or disk drives. However, in a system where the shared non-volatile memory storage devices each have a single port accessible through a host control processor, excessive latency may be experienced in memory accesses from dedicated functions in specific processors due to increased interdependencies between subsystems and overhead of inter-process communication (IPC). Also, debug in such a system may become unacceptably complicated.